Garmin HRM dual - remove module after use

Question

I recently purchased a Garmin Dual HRM belt; should I remove the center module after each use? In the manual it is stated that it can prologue the life-time; but I want to know what other users do.

My best regards,

Answer 1

Heart rate monitors (HRMs) have the module itself, which houses the battery and the circuitry (and the optical sensors, if it's an optical HRM), and a strap, which has electrodes and snap closures if it's a chest HRM.

Garmin's manual entry on maintenance says to rinse the strap after every use, and machine wash after every seven uses. I think that this is received wisdom in general. Salt and bacteria will otherwise build up in the strap fabric and shorten its life. You could also hand wash the strap in the shower, which I do often. That is the key to maintenance of the strap. For better or worse, the straps are long-term consumable items, and you could expect to buy more than one strap over the lifetime of a good HRM.¹

For chest HRMs (like the OP's), when both snaps are connected, the HRM may think that there's a completed circuit, and it may scan for a heartbeat and activate its transmitters. This consumes power, and that's the reason for the recommendation. Naturally, while the units are waterproof, they are absolutely not proof against conditions inside a washing machine, and thus it would seem completely logical to take the module off entirely when washing the strap in the machine.

Footnotes

1. If you have inconsistent heart rate readings, e.g. they don't sync up with perceived effort, replacing the battery or the strap may be one thing to try before getting a new HRM.

Answer 2

I've used Garmin HR monitors in my racing days, and to be honest, I never really bothered removing the unit from the belt after a ride. Regardless of that, the battery life was more than satisfactory - I don't remember having to replace the battery more often than once every few months with up to 20 hours of usage a week. Moreover, some Garmin HR monitors are actually designed as an integral part of the belt, making their removal impossible. I'd say taht as long as you store the device in a dry environment with no contact between the electrodes, there should be no difference in the battery life.